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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Pohon svislého suportu obráběcího centra lineárním motorem / Drive Vertical Saddle of Machining Centre by Linear Motor

Zapletal, Radek January 2008 (has links)
The diploma dissertation deals with the mechanism of vertical movement of a saddle of high-speed machining centre which is made by the Trimill company. The movement of vertical alloy saddle is solved by ball screw. The solution could be improved by replacing the ball screw by linear motor. This will dramatically improve the dynamics of the movement of the vertical saddle. In addition, if the weight is compensated by pneumatic relief and the construction is welded, the dynamics will further improve.
12

Bezsnímačové řízení střídavých motorů na platformě STM32 / Sensorless control of AC motors on STM32 platform

Soviš, Jiří January 2021 (has links)
The thesis is focused on the issue of sensorless vector control of a synchronous motor with permanent magnets in the low-speed range. In the first part, there is a brief description of the synchronous motor and the necessary transformations for the application of vector control. This is followed by the overview of sensorless methods for position estimation by injecting a high-frequency harmonic signal. The practical part is devoted to the implementation of a control algorithm to develop kit STM32NUCLEO-L476RG, which is preceded by the identification of all engine parameters. As part of the implementation, a structure including current, speed and position control was designed. The functionality and robustness of the settings have been successfully tested due to the different inertia and load.
13

Palubní počítač pro motocykl / Motorcycle on-board computer

Hadwiger, Tomáš January 2011 (has links)
My thesis deals with the construction of on-board computers for a motorcycle. The scheme is based on the parameters of onboard computers appearing on the market. In comparison with the models, which are offered commercially it also allows measurement of the motorcycle’s fuel consumption and location by using GPS. On-board computer measures speed, traveled distance, motor speed and engine temperature. It is controlled by a pair of eight-bit AVR microcontrollers. The measured data are showed by a graphical LCD display with touch screen.
14

Porovnání motorických schopností párových a nepárových veslařů / Comparison of motor abilities of pair and unpaired rowers

Mocek, Karel January 2014 (has links)
Theme in this thesis is comparison of motor abilities of pair and unpaired rowers. There is briefly mentioned characteristic of rowing and structure of rowing performance in theoretical part. Next captures are about single motor abilities. In practical part of thesis are characterized rowers, who were tested and Unifittes 6-60, according to were rowers tested. Last part of thesis is about comparison of measured results. Key words Rower, rowing, pair rowing, unpaired rowing, motor, motor abilities, movement, tests, motor testing, power abilities, speed abilities, endurance abilities, coordination abilities.
15

Quantitative measurements of temperature using laser-induced thermal grating spectroscopy in reacting and non-reacting flows

Lowe, Steven January 2018 (has links)
This thesis is concerned with the development and application of laser induced thermal grating spectroscopy (LITGS) as a tool for thermometry in reacting and non-reacting flows. LITGS signals, which require resonant excitation of an absorbing species in the measurement region to produce a thermal grating, are acquired for systematic measurements of temperature in high pressure flames using OH and NO as target absorbing species in the burned gas. The signal obtained in LITGS measurements appears in the form of a time-based signal with a characteristic frequency proportional to the value or the sound speed of the local medium. With knowledge of the gas composition, the temperature can be derived from the speed of sound measurement. LITGS thermometry using resonant excitation of OH in the burned gas region of in oxygen enriched CH4/O2/N2 and CH4/air laminar flames was performed at elevated pressure (0.5 MPa) for a range of conditions. Measurements were acquired in oxygen enriched flames to provide an environment in which to demonstrate LITGS thermometry under high temperature conditions (up to 2900 K). The primary parameters that influence the quality of LITGS signal were also investigated. The signal contrast, which acts as a marker for the strength of the frequency oscillations, is shown to increase with an increase in the burnt gas density at the measurement point. LITGS employing resonant excitation of NO is also demonstrated for quantitative measurements of temperature in three environments – a static pressure cell at ambient temperature, a non-reacting heated jet at ambient pressure and a laminar premixed CH4/NH3/air flame operating at 0.5 MPa. Flame temperature measurements were acquired at various locations in the burned gas close to a water-cooled stagnation plate, demonstrating the capability of NO-LITGS thermometry for measuring the spatial distribution of temperature in combustion environments. In addition, the parameters that in influence the local temperature rise due to LITGS were also investigated in continuous vapour flows of acetone/air and toluene/air mixtures at atmospheric conditions. Acetone and toluene are commonly targeted species in previous LITGS measurements due to their favourable absorption characteristics. Results indicate that LITGS has the potential to produce accurate and precise measurements of temperature in non-reacting flows, but that the product of the pump intensity at the probe volume and the absorber concentration must remain relatively low to avoid significant localised heating of the measurement region.

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